// random main images
var mainImages = new Array() 
mainImages[0] = '/common/images/main/image1.jpg'
mainImages[1] = '/common/images/main/image2.jpg'
mainImages[2] = '/common/images/main/image3.jpg'
mainImages[3] = '/common/images/main/image4.jpg'

	var j = 0
	var l = mainImages.length;
	var preBuffer = new Array()
	for (i = 0; i < l; i++){
  	 preBuffer[i] = new Image()
  	 preBuffer[i].src = mainImages[i]
	}
	function newmainImage() {
	var whichmainImage = Math.round(Math.random()*(l-1));
	document.mainImage.src = mainImages[whichmainImage]
	document.mainImage.src = preBuffer[whichmainImage].src
	}